Purpose. To analyze the levels of diadenosine tetraphosphate (Ap4A) and diadenosine pentaphosphate (Ap5A) in tears of subjects with Sjögren Syndrome and to compare with a control group.

Methods. Twelve subjects, diagnosed with Sjögren Syndrome, and 20 healthy subjects such as control, were invited to participate in the present study. Schirmer strips were used to measure tear secretion (Schirmer I test) and to collect tears. Ap4A and Ap5A were measured by high pressure liquid chromatography (HPLC) and a Dry Eye Questionnaire (DEQ) was used to evaluated dry eye symptomatology.

Results. The mean concentrations of Ap4A and Ap5A in the Sjögren Syndrome group were 2.54 +/- 1.02 microM and 26.13 +/- 6.95 microM respectively. This group of patients was divided in two groups, four patients with normal tear production and eight patients with low tear production. Concentrations of Ap4A, and Ap5A, in patients with normal tear production (Schirmer test value of 12.3 +/- 1.2 mm), were 0.47 +/- 0.20 microM and 8.03 +/- 3.27 microM respectively. In the patients with low tear production (Schirmer test value of 1.0 +/- 0.3mm) the Ap4A and Ap5A concentrations were 4.09 +/- 1.36 microM and 39.51 +/- 8.46 microM, respectively. In the control group the Ap4A and Ap5A concentrations were 0.13 +/- 0.03 microM and 0.04 +/- 0.02 microM, respectively.

Conclusions. It is concluded that patients with Sjögren Syndrome have abnormally elevated concentrations of diadenosine polyphosphates indicating that these compounds could be used for the diagnosis of this pathology.